John C. Riley of Milton NH John C. Riley, 41, of Milton, is facing charges of sexual assault and kidnapping. (Portsmouth Police Department)

PORTSMOUTH — A Milton man who worked at a local agency that provides support services to adults with developmental disabilities has been arrested on charges of sexual assault, kidnapping and indecent exposure.

Portsmouth police announced the arrest of 41-year-old John C. Riley Thursday evening after taking him into custody earlier in the day.

Police say Riley had access to his alleged victim “through his employment” at the unnamed support services agency. They have not specified whether the victim was a client of the agency.

Riley faces class A felony charges of aggravated sexual assault and kidnapping. The indecent exposure allegation is a misdemeanor-level offense.

Riley, who lives at 1147 White Mountain Highway in Milton, has been ordered held on $30,000 cash bail, according to Portsmouth police. He was being held Thursday at the Rockingham County House of Corrections.

Police are asking anyone with information concerning the investigation to contact Detective Tim Cashman at 603-610-7587.

Those individuals who wish to remain anonymous may call Crime Stoppers at 431-1199 or 207-439-1199. People may also make a report through the Crime Stoppers website www.seacoastcrimestoppers.org.

Fosters.com will provide more information about this story as it becomes available.